I would call it a warning sign that it needs to be rebuilt, so I would factor that into the price. While I do not have any direct experience with DeVilbiss compressors, from the parts list, it looks like it is a very well built machine. And it seems that parts are still available. If found the site below that has the parts list/parts:
http://www.devilbissparts.com/devilbiss/air_compressors/stat-pumps.html
Looks like you would need the two running gear kits and a gasket kit, at the minimum. I would also suggest that you consider replacing the crankshaft bearings (which you may be able to get at a bearing house, cheaper) and consider going through the valves. Well, after checking the prices, you might want to reconsider, it looks like the two running gear kits are over $700. Maybe just go with rings, which are over $200 for both sets. Or maybe you can find better prices elsewhere. Of course, the issue is that without tearing it down, you are not really sure what all it may need.
Think of these types of compressors as being similar to an internal combustion engine when it comes to rebuilding. The cylinders and crank journals may need some work, if things have gone too far. But, it sounds like this one is still running, so it should not be in too bad of shape, provided it sounds pretty smooth. Although, you may want to hone the cylinders, prior to installing the new rings.
I'm not sure what the new cost of this unit was/is, but I do know that a similar Qunicy unit is in the $1500-2000 range. If you will be using a lot of air on a continual basis (for something like sandblasting) then this is the range of unit that I would look at. However, if your air usage is more occasional and smaller volume, then the investment for this unit may exceed the cost of a brand new lower end unit that may work just fine for you.
- David
